64. Potential Theft of a Mezuzah
11:8 Some gateways have a small doorway adjacent to the large gate. People regularly pass through this doorway, saving the large gate for infrequent usage. Since there are two discrete entrances, separated by a pillar of at least a hand-breadth in width (around 3.5 inches), each entrance requires its own mezuzah.
11:9 If one has a reasonable concern that his mezuzah might be stolen, he should make a hole in the doorpost and place the mezuzah inside of it. This hole may not be deeper than a hand-breadth (again, about 3.5 inches) because then the mezuzah would no longer be considered “on the doorposts of your house” (as per Deuteronomy 6:9 and 11:20). In any event, a person should ensure that the location of the mezuzah is recognizable. If it is not possible to make a such a hole in the doorpost, one can rely on the opinions that allow attaching the mezuzah on the inside, behind the door. In such a case, the mezuzah must still be attached to the doorpost, not the wall. Furthermore, the mezuzah must be placed within a hand-breadth of the entryway or it is invalid.